ORAU Lead Technical Evaluator: Joseph Guido ORAU Review Completed By: Michael Kubiak 

SEC Petition Evaluation Report 

Petition SEC-00133 

Report Rev #: 0 Report Submittal Date: December 1, 2008 

Subject Expert(s): Joseph Guido 

Site Expert(s): N/A 

Petitioner Administrative Summary 

Petition Under Evaluation 

Petition # Petition 

Type 

Petition A 

Receipt Date DOE/AWE Facility Name 

SEC-00133 83.14 November 18, 2008 Mallinckrodt Chemical Co., Destrehan Street Plant 

NIOSH-Proposed Class Definition 

All employees of DOE, its predecessor agencies, and their contractors and subcontractors who worked in the 

Uranium Division at the Mallinckrodt Chemical Co., Destrehan Street Plant in St. Louis, Missouri, from 

January 1, 1958 to December 31, 1958, for a number of work days aggregating at least 250 work days, 

occurring either solely under this employment or in combination with work days within the parameters 

established for one or more other classes of employees included in the SEC. 

Related Petition Summary Information 

SEC Petition 

Tracking #(s) Petition Type DOE/AWE Facility Name Petition Status 

SEC-00012 83.13 Mallinckrodt Chemical Co., SEC-00012-1 Added to SEC 

Destrehan Street Plant SEC-00012-2 Added to SEC 

Related Evaluation Report Information 

Report Title DOE/AWE Facility Name 

SEC Petition Evaluation Report SEC-00012-2 Mallinckrodt Chemical Co., Destrehan Street Plant 

Peer Review Completed By: [Signature on file] 

LaVon Rutherford 

12/01/2008 

Date 

SEC Petition Evaluation Reviewed By: [Signature on file] 

J. W. Neton 

12/01/2008 

Date 

SEC Evaluation Approved By: [Signature on file] 

Larry Elliott 

12/01/2008 

Date 
SEC-00133 12-01-08 FINAL Mallinckrodt Chemical Co. 

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Evaluation Report Summary: SEC-00133, Mallinckrodt Chemical Co., 

Destrehan Street Plant 

This evaluation report by the National Institute for Occupational Safety and Health (NIOSH) 

addresses a class of employees proposed for addition to the Special Exposure Cohort (SEC) per the 

Energy Employees Occupational Illness Compensation Program Act of 2000, as amended, 42 U.S.C. 

§ 7384 et seq. (EEOICPA) and 42 C.F.R. pt. 83, Procedures for Designating Classes of Employees 

as Members of the Special Exposure Cohort Under the Energy Employees Occupational Illness 

Compensation Program Act of 2000. 

NIOSH-Proposed Class Definition 

All employees of the Department of Energy (DOE), its predecessor agencies, and their contractors and 

subcontractors who worked in the Uranium Division at the Mallinckrodt Chemical Co., Destrehan 

Street Plant in St. Louis, Missouri from January 1, 1958 to December 31, 1958, for a number of work 

days aggregating at least 250 work days, occurring either solely under this employment or in 

combination with work days within the parameters established for one or more other classes of 

employees included in the SEC. 

Feasibility of Dose Reconstruction Findings 

NIOSH lacks sufficient information, which includes specific monitoring data, sufficient air 

monitoring information, and sufficient process and radiological source information, to allow it to 

estimate with sufficient accuracy the potential internal exposures to uranium progeny present in 

pitchblende raffinate (e.g., thorium-230, protactinium-231, and actinium-227) to which the proposed 

class may have been subjected. 

NIOSH finds that it likely is feasible to reconstruct both individual external dose and occupational 

medical dose for Mallinckrodt Chemical Co., Destrehan Street Plant workers with sufficient accuracy. 

•	 Throughout 1958, the Mallinckrodt Chemical Co., Destrehan Street Plant continued to handle 

residues from the processing of uranium ore, known to contain equilibrium activities of 

radionuclides present in the natural uranium decay series. After uranium was extracted from the 

pitchblende ore, residues known as raffinate were generated. The uranium progeny in the 

pitchblende raffinate (e.g., thorium-230, protactinium-231, and actinium-227) were known to be 

present in substantial disequilibrium. The collection and storage of the raffinate at the Destrehan 

Street Plant continued to represent a significant potential source term for internal exposure through 

December 31, 1958. 

•	 There is no individual bioassay monitoring or other monitoring information that can be used to 

quantify internal exposures to thorium-230, protactinium-231, and actinium-227 for raffinate 

workers specifically at the Mallinckrodt Chemical Co., Destrehan Street Plant for the period 

January 1, 1958 through December 31, 1958. 

•	 The specific air sample data that exist for the Mallinckrodt Chemical Co., Destrehan Street Plant 

are insufficient to establish the internal doses from inhalation of thorium-230, protactinium-231, 

and actinium-227 with sufficient accuracy for the period from January 1, 1958 through December 

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31, 1958. This is because 1) the air sample data found at the Mallinckrodt Chemical Co., 

Destrehan Street Plant do not provide radionuclide-specific information for the site; and 2) very 

few data are available to characterize the degree of disequilibrium in the raffinate source term at 

the Mallinckrodt Chemical Co., Destrehan Street Plant. 

•	 Records from the Mallinckrodt Chemical Co., Destrehan Street Plant indicate that during 1958, 

employees may have rotated through a number of different jobs. The changes in work 

assignments make it difficult to distinguish the raffinate-exposed workers from the workers who 

never worked with raffinate. 

•	 Pursuant to 42 C.F.R. § 83.13(c)(1), NIOSH determined that there is insufficient information to 

either: (1) estimate the maximum radiation dose, for every type of cancer for which radiation 

doses are reconstructed, that could have been incurred under plausible circumstances by any 

member of the class; or (2) estimate the radiation doses of members of the class more precisely 

than a maximum dose estimate. 

•	 Although NIOSH found that it is not possible to completely reconstruct radiation doses for 

Mallinckrodt Chemical Co., Destrehan Street Plant employees, NIOSH intends to use any 

available internal and external monitoring data that may be available for an individual claim (and 

can be interpreted using existing NIOSH dose reconstruction processes or procedures). Further, 

NIOSH has determined that occupational medical dose for all workers can be reconstructed. 

Therefore, dose reconstructions for individuals with non-presumptive cancers or fewer than 250 

days employment in the class period may be performed using these data as appropriate. 

Health Endangerment Determination 

The NIOSH evaluation did not identify any evidence supplied by the petitioners or from other 

resources that would establish that the class was exposed to radiation during a discrete incident likely 

to have involved exceptionally high-level exposures, such as nuclear criticality incidents or other 

events involving similarly high levels of exposures. However, the evidence reviewed in this 

evaluation indicates that some workers in the class may have accumulated chronic radiation exposures 

through intakes of uranium and uranium progeny and from direct exposure to radioactive materials. 

Therefore, 42 C.F.R. § 83.13(c)(3)(ii) requires NIOSH to specify that health may have been 

endangered for those workers covered by this evaluation who were employed for a number of work 

days aggregating at least 250 work days within the parameters established for this class or in 

combination with work days within the parameters established for one or more other classes of 

employees in the SEC. 

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Table of Contents 

Evaluation Report Summary: SEC-00133, Mallinckrodt Chemical Co., Destrehan Street Plant ........... 3
 

1.0 Purpose and Scope....................................................................................................................... 7
 

2.0 Introduction ................................................................................................................................. 7
 

3.0 NIOSH-Proposed Class Definition and Petition Basis................................................................ 8
 

4.0 Radiological Operations Relevant to the Proposed Class ........................................................... 9 

4.1 Operations Description ....................................................................................................... 9 

4.2 Radiation Exposure Potential from Operations ................................................................ 10 

4.3 Time Period Associated with Radiological Operations.................................................... 10 

4.4 Site Locations Associated with Radiological Operations ................................................ 10 

4.5 Job Descriptions Affected by Radiological Operations ................................................... 10
 

5.0 Summary of Available Monitoring Data for the Proposed Class .............................................. 11 

5.1 Data Capture Efforts and Sources Reviewed ................................................................... 11 

5.2 Internal Personnel Monitoring Data ................................................................................. 12 

5.3 External Personnel Monitoring Data ................................................................................ 12 

5.4 Workplace Monitoring Data............................................................................................. 12 

5.5 Radiological Source Term Data ....................................................................................... 13
 

6.0 Feasibility of Dose Reconstruction for the Proposed Class ...................................................... 13 

6.1 Feasibility of Estimating Internal Exposures ................................................................... 14 

6.2 Feasibility of Estimating External Exposures .................................................................. 15 

6.3 Class Parameters Associated with Infeasibility................................................................ 16
 

7.0 Summary of Feasibility Findings for Petition SEC-00133........................................................ 16
 

8.0 Evaluation of Health Endangerment for Petition SEC-00133................................................... 17
 

9.0 NIOSH-Proposed Class for Petition SEC-00133 ...................................................................... 17
 

10.0 Evaluation of Second Similar Class .......................................................................................... 17
 

11.0 References ................................................................................................................................. 19 

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SEC Petition Evaluation Report for SEC-00133
 

ATTRIBUTION AND ANNOTATION: This is a single-author document. All conclusions drawn from 

the data presented in this evaluation were made by the ORAU Team Lead Technical Evaluator: 

Joseph Guido, MJW Corporation, Inc. These conclusions were peer-reviewed by the individuals 

listed on the cover page. The rationales for all conclusions in this document are explained in the 

associated text. 

1.0 Purpose and Scope 

This report evaluates the feasibility of reconstructing doses for employees who worked at 

Mallinckrodt Chemical Co., Destrehan Street Plant in 1958. It provides information and analysis 

germane to considering a petition for adding a class of employees to the Congressionally-created SEC. 

This report does not make any determinations concerning the feasibility of dose reconstruction that 

necessarily apply to any individual energy employee who might require a dose reconstruction from 

NIOSH, with the exception of the employee whose dose reconstruction could not be completed, and 

whose claim consequently led to this petition evaluation. The finding in this report is not the final 

determination as to whether or not the proposed class will be added to the SEC. This report will be 

considered by the Advisory Board on Radiation and Worker Health (the Board) and by the Secretary 

of Health and Human Services (HHS). The Secretary of HHS will make final decisions concerning 

whether or not to add one or more classes to the SEC in response to the petition addressed by this 

report. 

This evaluation, in which NIOSH provides its findings both on the feasibility of estimating radiation 

doses of members of this class with sufficient accuracy and on health endangerment, was conducted in 

accordance with the requirements of EEOICPA and 42 C.F.R. § 83.14. 

2.0 Introduction 

Both EEOICPA and 42 C.F.R. pt. 83 require NIOSH to evaluate qualified petitions requesting that the 

Department of Health and Human Services add a class of employees to the SEC. The evaluation is 

intended to provide a fair, science-based determination of whether it is feasible to estimate, with 

sufficient accuracy, the radiation doses of the proposed class of employees through NIOSH dose 

reconstructions.1 

NIOSH is required to document its evaluation in a report, and to do so, relies upon both its own dose 

reconstruction expertise as well as technical support from its contractor, Oak Ridge Associated 

Universities (ORAU). Once completed, NIOSH provides the report to both the petitioners and the 

Advisory Board on Radiation and Worker Health. The Board will consider the NIOSH evaluation 

report, together with the petition, comments of the petitioner(s) and such other information as the 

Board considers appropriate, to make recommendations to the Secretary of HHS on whether or not to 

add one or more classes of employees to the SEC. Once NIOSH has received and considered the 

1

 NIOSH dose reconstructions under EEOICPA are performed using the methods promulgated under 42 C.F.R. pt. 82 and 

the detailed implementation guidelines available at http://www.cdc.gov/niosh/ocas. 

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SEC-00133 12-01-08 FINAL Mallinckrodt Chemical Co. 

advice of the Board, the Director of NIOSH will propose a decision on behalf of HHS. The Secretary 

of HHS will make the final decision, taking into account the NIOSH evaluation, the advice of the 

Board, and the proposed decision issued by NIOSH. As part of this final decision process, the 

petitioner(s) may seek a review of certain types of final decisions issued by the Secretary of HHS.2 

3.0 NIOSH-Proposed Class Definition and Petition Basis 

The NIOSH-proposed class includes all employees of DOE, its predecessor agencies, and their 

contractors and subcontractors who worked in the Uranium Division at the Mallinckrodt Chemical 

Co., Destrehan Street Plant in St. Louis, Missouri, from January 1, 1958 to December 31, 1958, for a 

number of work days aggregating at least 250 work days, occurring either solely under this 

employment or in combination with work days within the parameters established for one or more 

other classes of employees included in the SEC. During this period, employees at this facility handled 

residues from the processing of uranium ore involving exposures to uranium and uranium progeny. 

The evaluation responds to Petition SEC-00133, which was submitted by an EEOICPA claimant 

whose dose reconstruction could not be completed by NIOSH due to a lack of sufficient dosimetryrelated information. This claimant was employed as a clerk/typist from 1957 through 1960. NIOSH’s 

determination that it is unable to complete a dose reconstruction for an EEOICPA claimant is a 

qualified basis for submitting an SEC petition pursuant to 42 C.F.R. § 83.9(b). 

The proposed class is based on the NIOSH determination that the radiological conditions in 1958 at 

the Destrehan Street Plant are indistinguishable from the conditions that existed in 1957. On October 

14, 2005, HHS designated a class of Mallinckrodt Chemical Co. employees for addition to the SEC 

(HHS, 2005). The designation became effective on November 13, 2005, and included the class of 

employees who worked in the Uranium Division from 1949 to 1957. The HHS findings relating to 

the period from 1949 through 1957 are summarized below: 

•	 Between 1949 and 1957, the Mallinckrodt facility processed large quantities of pitchblende ore, 

known to contain equilibrium activities of radionuclides present in the natural uranium decay 

series. After uranium was extracted from the pitchblende ore, more than 100,000 tons of residues, 

known as raffinate, were generated. The uranium progeny in the pitchblende raffinate (e.g., 

thorium-230, protactinium-231, and actinium-227) were known to be present in substantial 

disequilibrium. The collection and storage of the raffinate at the Destrehan Street facility of 

Mallinckrodt Chemical Works represent a significant potential source term for internal exposure 

(HHS, 2005). 

•	 There is not individual bioassay monitoring or other monitoring information that can be used to 

quantify internal exposures to thorium-230, protactinium-231, and actinium-227 for raffinate 

workers specifically at the Destrehan Street facility of the Mallinckrodt Chemical Works for the 

period 1949 through 1957 (HHS, 2005). 

2 See 42 C.F.R. pt. 83 for a full description of the procedures summarized here. Additional internal procedures are 

available at http://www.cdc.gov/niosh/ocas. 

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•	 The specific air sample data that exist for the Destrehan Street facility of Mallinckrodt Chemical 

Works are insufficient to establish the internal doses from inhalation of thorium-230, 

protactinium-231, and actinium-227 at the site with sufficient accuracy for the period from 1949 

through 1957. This is because 1) the air sample data found at the Destrehan Street facility of 

Mallinckrodt Chemical Works do not provide radionuclide-specific information for the site; and 2) 

very little data are available to characterize the degree of disequilibrium in the raffinate source 

term at the Destrehan Street facility of Mallinckrodt Chemical Works (HHS, 2005). 

•	 Records from the Destrehan Street facility of Mallinckrodt Chemical Works indicate that during 

the time frame 1949-1957, employees may have rotated through a number of different jobs. The 

changes in work assignments make it difficult to distinguish the raffinate-exposed workers from 

the workers who never worked with raffinate (HHS, 2005). 

4.0 Radiological Operations Relevant to the Proposed Class 

The following subsections summarize the radiological operations at the Mallinckrodt Chemical Co., 

Destrehan Street Plant from January 1, 1958 to December 31, 1958 and the information available to 

NIOSH to characterize particular processes and radioactive source materials. Using available sources, 

NIOSH has attempted to gather process and source descriptions, information regarding the identity 

and quantities of radionuclides of concern, and information describing processes through which the 

radiation exposures of concern may have occurred and the physical environment in which they may 

have occurred. The information included within this evaluation report is meant only to be a summary 

of the available information. 

4.1 Operations Description 

A detailed description of process operations at the Mallinckrodt Chemical Co., Destrehan Street Plant 

can be found in the NIOSH Site Profile document Basis for Development of an Exposure Matrix for 

the Mallinckrodt Chemical Company St. Louis Downtown Site and the St. Louis Airport Site, St. 

Louis, Missouri (ORAUT-TKBS-0005). The Mallinckrodt Chemical Co., Destrehan Street Plant 

refined uranium under contract to the United States Government from 1942 to 1958. While site 

activities continued until 1962, sometime in 1957 or 1958, all uranium refining operations ceased and 

the work moved from the Destrehan Street Plant to Fernald and Weldon Spring (USACE, 2003; 

Cooperstein, 1981). All Mallinckrodt Plant 6 work, which at that time included processing steps 

through uranium oxide production, was transferred to Weldon Spring in March 1957 (Eisenbud, 

1975). Some Mallinckrodt Plant 7 production operations continued through July 1958 (possibly to 

exhaust the store of orange oxide that had already been produced at the Destrehan Plant) before they 

were transferred to Weldon Spring (Mason, 1959). Mallinckrodt documents support the conclusion 

that the Mallinckrodt Chemical Co., Destrehan Street Plant was put on standby in 1958 (Mallinckrodt, 

1994). Therefore, NIOSH concludes that the radiological conditions upon which the 1949 to 1957 

SEC class is based continued into 1958. 

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4.2 Radiation Exposure Potential from Operations 

The potential for external and internal radiation dose existed at the Mallinckrodt Chemical Co., 

Destrehan Street Plant. Based on the site operations outlined in Section 4.1, Mallinckrodt Chemical 

Co., Destrehan Street Plant sources of exposure in 1958 included uranium and uranium progeny. 

Similar to the sources of exposure during the previously designated SEC period from 1949 through 

1957, the 1958 exposures potentially included uranium progeny present in pitchblende raffinate (e.g., 

thorium-230, protactinium-231, and actinium-227), known to be present in substantial disequilibrium. 

Specific exposure conditions during the period from 1949 through 1957 are discussed in the NIOSH 

SEC Petition Evaluation Reports for SEC-00012 (SEC-00012-1 and SEC-00012-2) and ORAUTTKBS-0005. 

4.3 Time Period Associated with Radiological Operations 

Per the DOE Office of Health, Safety and Security, the time period associated with DOE operations at 

the Mallinckrodt Chemical Co., Destrehan Street Plant is from 1942 through 1962 (DOE, 2008). HHS 

has previously designated SEC classes for employment at the Destrehan Street Plant during the 

periods 1942 through 1948, and 1949 through 1957. Based on the site operations and exposure 

conditions outlined in Sections 4.1 and 4.2, NIOSH has concluded that similar operations and 

exposure conditions continued into 1958. NIOSH has found no substantive difference in site 

operations, personnel and workplace monitoring, source term, or available site characterization data 

between 1958 and the previously designated SEC period from 1949 through 1957. After uranium 

refining operations ended in 1958, plant operations consisted of decontamination and 

decommissioning activities (ORAUT-TKBS-0005). Because NIOSH is unable to determine (using 

available documentation) exactly when in 1958 uranium operations were completed at the Destrehan 

Street Plant, NIOSH has assigned a date of December 31, 1958 for the cessation of uranium refining 

operations. 

4.4 Site Locations Associated with Radiological Operations 

The radiological conditions and work processes conducted throughout the Mallinckrodt Chemical Co., 

Destrehan Street Plant in 1958, and during earlier periods, are discussed in the NIOSH SEC Petition 

Evaluation Reports for SEC-00012 (SEC-00012-1 and SEC-00012-2) and in ORAUT-TKBS-0005. 

The current SEC class for Uranium Division workers employed during the period from 1949 through 

1957 is not administered based on site work locations. Based on the site operations and exposure 

conditions outlined in Sections 4.1 and 4.2 of this report, NIOSH has found no substantive difference 

in site operations, personnel and workplace monitoring, source term, or available site characterization 

data between 1958 and the previously designated SEC period from 1949 through 1957. As with the 

earlier 1949 through 1957 SEC period, NIOSH does not have sufficient information for 1958 

regarding the receipt, transport, or storage of uranium raffinate onsite to enable NIOSH to limit any 

1958 SEC class based on work location within the Mallinckrodt Chemical Co., Destrehan Street Plant. 

4.5 Job Descriptions Affected by Radiological Operations 

On October 14, 2005, HHS designated a class of Mallinckrodt Chemical Co. employees for addition 

to the SEC (HHS, 2005). This class included “DOE employees or DOE contractor or subcontractor 

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employees who worked in the Uranium Division at the Destrehan Street facility of Mallinckrodt 

Chemical Works from 1949 to 1957 ...” 

HHS based the class description on findings that records from the Destrehan Street facility of 

Mallinckrodt Chemical Works indicate that during the 1949 through 1957 timeframe, employees may 

have rotated through a number of different jobs; these changes in work assignments made it difficult 

to distinguish the raffinate-exposed workers from the workers who never worked with raffinate (HHS, 

2005). 

Based on the site operations and exposure conditions outlined in Sections 4.1 and 4.2 of the report, 

NIOSH has concluded that handling of residues from processing of uranium ore continued into 1958. 

NIOSH has found no substantive difference in site operations, personnel and workplace monitoring, 

source term, or available site characterization data between 1958 and the previously designated SEC 

period from 1949 through 1957. As with the earlier 1949 through 1957 SEC period, NIOSH does not 

have sufficient information for 1958 to distinguish the raffinate-exposed workers from the workers 

who never worked with raffinate. Therefore, NIOSH is unable to limit any 1958 SEC class more 

specifically than the class description designated by HHS for the existing 1949 through 1957 SEC 

class (HHS, 2005). 

5.0 Summary of Available Monitoring Data for the Proposed Class 

The primary data used for determining internal exposures are derived from personal monitoring data, 

such as urinalyses, fecal samples, and whole-body counting results. If these are unavailable, the air 

monitoring data from breathing zone and general area monitoring are used to estimate the potential 

internal exposure. If personal monitoring and breathing zone area monitoring are unavailable, internal 

exposures can sometimes be estimated using more general area monitoring, process information, and 

information characterizing and quantifying the source term. 

This same hierarchy is used for determining the external exposures to the cancer site. Personal 

monitoring data from film badges or thermoluminescent dosimeters (TLDs) are the primary data used 

to determine such external exposures. If there are no personal monitoring data, exposure rate surveys, 

process knowledge, and source term modeling can sometimes be used to reconstruct the potential 

exposure. 

A more detailed discussion of the information required for dose reconstruction can be found in 

OCAS-IG-001, External Dose Reconstruction Implementation Guideline, and OCAS-IG-002, Internal 

Dose Reconstruction Implementation Guideline. These documents are available at: 

http://www.cdc.gov/niosh/ocas/ocasdose.html. 

5.1 Data Capture Efforts and Sources Reviewed 

In addition to examining its Site Research Database (SRDB) to locate documents supporting its 

evaluation of the proposed class, NIOSH has reviewed the site-specific information discussed in the 

NIOSH SEC Petition Evaluation Reports for SEC-00012 (SEC-00012-1 and SEC-00012-2) and 

ORAUT-TKBS-0005 to locate information relevant to determining the feasibility of dose 

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reconstruction for the class of employees proposed for this petition. This included a review of 

information on personnel monitoring, workplace monitoring, and radiological source term data. 

5.2 Internal Personnel Monitoring Data 

A detailed description of personnel monitoring practices and available internal monitoring data for the 

Mallinckrodt Chemical Co., Destrehan Street Plant can be found in ORAUT-TKBS-0005. Uranium 

urinalysis results are generally available for Mallinckrodt Destrehan Street Plant workers during the 

period from January 1, 1958 through December 31, 1958. 

In its designation of a Mallinckrodt SEC class for the period 1949 through 1957, HHS found that there 

was no individual bioassay monitoring, or other monitoring, information that could be used to 

quantify internal exposures to thorium-230, protactinium-231, and actinium-227 for raffinate workers 

specifically at the Destrehan Street facility of Mallinckrodt Chemical Works for the period 1949 

through 1957 (HHS, 2005). 

Based on a NIOSH review of claimant internal monitoring data available for workers employed in 

1958 and the site operations and exposure conditions outlined in Sections 4.1 and 4.2, NIOSH has 

found no substantive difference in the availability of internal monitoring data between 1958 and the 

previously designated SEC period from 1949 through 1957. 

5.3 External Personnel Monitoring Data 

A detailed description of personnel monitoring practices and available external monitoring data for the 

Mallinckrodt Chemical Co., Destrehan Street Plant can be found in ORAUT-TKBS-0005. External 

dosimetry results are generally available for Mallinckrodt Chemical Co., Destrehan Street Plant 

workers during the period from January 1, 1958 through December 31, 1958. 

In its designation of a Mallinckrodt SEC class for the period 1949 through 1957, HHS indicated that 

the available external dose monitoring information was adequate for the reconstruction of individual 

exposures for the period from 1949 through 1957 (HHS, 2005). 

Based on a NIOSH review of the claimant external monitoring data available for workers employed in 

1958 and the site operations and exposure conditions outlined in Sections 4.1 and 4.2, NIOSH has 

found no substantive difference in the availability of external monitoring data between 1958 and the 

previously designated SEC period from 1949 through 1957. 

5.4 Workplace Monitoring Data 

A detailed description of workplace monitoring practices and available workplace monitoring data for 

the Mallinckrodt Chemical Co., Destrehan Street Plant can be found in ORAUT-TKBS-0005. Some 

records of workplace surface and air monitoring data, including general area air samples and worker 

dust exposure studies (time-weighted exposures), are available for the period from January 1, 1958 

through December 31, 1958. 

In its designation of a Mallinckrodt SEC class for the period 1949 through 1957, HHS found that 

specific air sample data that exist for the Destrehan Street facility were insufficient to establish the 

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internal doses from inhalation of thorium-230, protactinium-231, and actinium-227 with sufficient 

accuracy for the period 1949 through 1957. This is because 1) the air sample data found at Destrehan 

Street facility of Mallinckrodt Chemical Works do not provide radionuclide-specific information for 

the site; and 2) very few data are available to characterize the degree of disequilibrium in the raffinate 

source term at the Destrehan Street facility of Mallinckrodt Chemical Works (HHS, 2005). 

Based on a NIOSH review of available workplace monitoring data and the site operations and 

exposure conditions outlined in Sections 4.1 and 4.2, NIOSH has found no substantive difference in 

the availability of workplace monitoring data between 1958 and the previously designated SEC period 

from 1949 through 1957. 

5.5 Radiological Source Term Data 

A detailed description of process operations and available source term data for the Mallinckrodt 

Chemical Co., Destrehan Street Plant can be found in ORAUT-TKBS-0005. The primary mission at 

the Mallinckrodt Chemical Co., Destrehan Street Plant was the refining of uranium. Nuclides present 

at the site during the period from January 1, 1958 through December 31, 1958 included uranium and 

associated uranium progeny. 

In its designation of a Mallinckrodt SEC class for the period 1949 through 1957, HHS found that 

between 1949 and 1957, the Mallinckrodt facility processed large quantities of pitchblende ore, 

known to contain equilibrium activities of radionuclides present in the natural uranium decay series. 

After uranium was extracted from the pitchblende ore, more than 100,000 tons of residues, known as 

raffinate, were generated. The uranium progeny in the pitchblende raffinate (e.g., thorium-230, 

protactinium-231, and actinium-227) were known to be present in substantial disequilibrium. The 

collection and storage of the raffinate at the Destrehan Street facility of Mallinckrodt Chemical Works 

represented a significant potential source term for internal exposure (HHS, 2005). 

Based on a NIOSH review of available source term and workplace radiological data and the site 

operations and exposure conditions outlined in Sections 4.1 and 4.2 of this report, NIOSH has found 

no substantive difference in the radiological conditions or availability of source term data between 

1958 and the previously designated SEC period from 1949 through 1957. 

6.0 Feasibility of Dose Reconstruction for the Proposed Class 

42 C.F.R. § 83.14(b) states that HHS will consider a NIOSH determination that there was insufficient 

information to complete a dose reconstruction, as indicated in this present case, to be sufficient, 

without further consideration, to conclude that it is not feasible to estimate the levels of radiation 

doses of individual members of the class with sufficient accuracy. 

In the case of a petition submitted to NIOSH under 42 C.F.R. § 83.9(b), NIOSH has already 

determined that a dose reconstruction cannot be completed for an employee at the DOE or AWE 

facility. This determination by NIOSH provides the basis for the petition by the affected claimant. 

Per § 83.14(a), the NIOSH-proposed class defines those employees who, based on completed 

research, are similarly affected and for whom, as a class, dose reconstruction is similarly not feasible. 

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In accordance with § 83.14(a), NIOSH may establish a second class of coworkers at the facility for 

whom NIOSH believes that dose reconstruction is similarly infeasible, but for whom additional 

research and analysis is required. If so identified, NIOSH would address this second class in a 

separate SEC evaluation rather than delay consideration of the claim currently under evaluation (see 

Section 10). This would allow NIOSH, the Board, and HHS to complete, without delay, their 

consideration of the class that includes a claimant for whom NIOSH has already determined a dose 

reconstruction cannot be completed, and whose only possible remedy under EEOICPA is the addition 

of a class of employees to the SEC. 

This section of the report summarizes research findings by which NIOSH determined that it lacked 

sufficient information to complete the relevant dose reconstruction and on which basis it has defined 

the class of employees for which dose reconstruction is not feasible. NIOSH’s determination relies on 

the same statutory and regulatory criteria that govern consideration of all SEC petitions. 

6.1 Feasibility of Estimating Internal Exposures 

The proposed class is based on the NIOSH determination that the radiological conditions in 1958 at 

the Mallinckrodt Chemical Co., Destrehan Street Plant are indistinguishable from the conditions that 

existed at the end of the HHS-designated SEC class for Mallinckrodt Chemical Co. employees who 

worked in the Uranium Division from 1949 to 1957. Based on the site operations and exposure 

conditions outlined in Sections 4.1 and 4.2 of this report, NIOSH has concluded that handling of 

residues from processing of uranium ore continued into 1958, and that NIOSH has found no 

substantive difference in site operations, personnel and workplace monitoring, source term, or 

available site characterization data between 1958 and the previously designated SEC period from 

1949 through 1957. 

As presented in Section 4.3, after the shutdown of residue handling operations in 1958, plant 

operations consisted of decontamination and decommissioning activities (ORAUT-TKBS-0005). 

Because NIOSH is unable to determine (using available documentation) exactly when in 1958 

uranium operations were completed at the Destrehan Street Plant, NIOSH has assigned a date of 

December 31, 1958 for the cessation of uranium refining operations. 

Consistent with the HHS findings relative to the SEC-00012 class designated for the period from 1949 

through 1957, NIOSH here finds that: 

•	 Throughout 1958, the Mallinckrodt Chemical Co., Destrehan Street Plant continued to handle 

residues from processing of uranium ore, known to contain equilibrium activities of radionuclides 

present in the natural uranium decay series. After uranium was extracted from the pitchblende 

ore, residues known as raffinate were generated. The uranium progeny in the pitchblende raffinate 

(e.g., thorium-230, protactinium-231, and actinium-227) were known to be present in substantial 

disequilibrium. The collection and storage of the raffinate at the Destrehan Street Plant continued 

to represent a significant potential source term for internal exposure through December 31, 1958. 

•	 There is no individual bioassay monitoring, or other monitoring, information that can be used to 

quantify internal exposures to thorium-230, protactinium-231, and actinium-227 for raffinate 

workers specifically at the Mallinckrodt Chemical Co., Destrehan Street Plant for the period 

January 1, 1958 through December 31, 1958. 

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•	 The specific air sample data that exist for the Mallinckrodt Chemical Co., Destrehan Street Plant 

are insufficient to establish the internal doses from inhalation of thorium-230, protactinium-231, 

and actinium-227 with sufficient accuracy for the period from January 1, 1958 through December 

31, 1958. This is because 1) the air sample data found at the Mallinckrodt Chemical Co., 

Destrehan Street Plant do not provide radionuclide-specific information for the site; and 2) very 

few data are available to characterize the degree of disequilibrium in the raffinate source term at 

the Mallinckrodt Chemical Co., Destrehan Street Plant. 

•	 Records from the Mallinckrodt Chemical Co., Destrehan Street Plant indicate that during 1958, 

employees may have rotated through a number of different jobs. The changes in work 

assignments make it difficult to distinguish the raffinate-exposed workers from the workers who 

never worked with raffinate. 

NIOSH does not have access to sufficient personnel monitoring, workplace monitoring, or source 

term data to estimate potential internal exposures to uranium progeny in the pitchblende raffinate 

(e.g., thorium-230, protactinium-231, and actinium-227) during the period from January 1, 1958 

through December 31, 1958. Consequently, NIOSH finds that it is not feasible to estimate, with 

sufficient accuracy, internal exposures to uranium progeny in the pitchblende raffinate (e.g., thorium230, protactinium-231, and actinium-227) and resulting doses for the class of employees covered by 

this evaluation. 

Although NIOSH found that it is not possible to completely reconstruct internal radiation doses for the 

period from January 1, 1958 through December 31, 1958, NIOSH intends to use any available internal 

monitoring data that may become available for an individual claim (and can be interpreted using 

existing NIOSH dose reconstruction processes or procedures). Dose reconstructions for individuals 

employed at the Mallinckrodt Chemical Co., Destrehan Street Plant in 1958, but not qualifying for 

inclusion in the SEC, may be performed using these data as appropriate. 

6.2 Feasibility of Estimating External Exposures 

This evaluation responds to a petition based on NIOSH’s determination that internal radiation 

exposures to uranium progeny in the pitchblende raffinate (e.g., thorium-230, protactinium-231, and 

actinium-227) could not be reconstructed for a dose reconstruction referred to NIOSH by the 

Department of Labor (DOL). As noted above, HHS will consider this determination to be sufficient 

without further consideration to determine that it is not feasible to estimate the levels of radiation 

doses of individual members of the class with sufficient accuracy. Consequently, it is not necessary 

for NIOSH to fully evaluate the feasibility of reconstructing external radiation exposures for the class 

of workers covered by this report. 

Consistent with the HHS findings relative to the SEC-00012 class designated for the period from 1949 

through 1957, NIOSH finds that the external dose monitoring information available for 1958 is 

adequate for the reconstruction of individual external exposures at the Mallinckrodt Chemical Co., 

Destrehan Street Plant for the period from January 1, 1958 through December 31, 1958. NIOSH has 

determined that external dose and medical X-ray dose can likely be reconstructed for the period from 

January 1, 1958 through December 31, 1958 using guidance and methods presented in ORAUTTKBS-0005. 

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6.3 Class Parameters Associated with Infeasibility 

As outlined in Section 4.3 of this report, NIOSH has concluded that handling of residues from 

processing of uranium ore continued into 1958. After the shutdown of residue handling operations in 

1958, plant operations consisted of decontamination and decommissioning activities (for which dose 

reconstruction is possible) (ORAUT-TKBS-0005). NIOSH is unable to determine (using available 

documentation) exactly when in 1958 uranium refining operations were completed at the Mallinckrodt 

Chemical Co., Destrehan Street Plant (Mason, 1959). NIOSH recommends that the proposed class 

include all of 1958 and cover the period from January 1, 1958 through December 31, 1958. 

As outlined in Section 4.4 of this report (and consistent with the analysis of the previous 1949 through 

1957 SEC class documented in the SEC-00012 Evaluation Reports), the available information for 

1958 regarding the receipt, transport, or storage of uranium raffinate is insufficient to allow NIOSH to 

define the proposed class based on work locations within the Mallinckrodt Chemical Co., Destrehan 

Street Plant. NIOSH recommends that the proposed class definition include all buildings during the 

specified time period. 

As outlined in Section 4.5 of this report, Mallinckrodt Chemical Co., Destrehan Street Plant 

employees may have rotated through a number of different jobs. NIOSH does not have sufficient 

information for 1958 to distinguish the raffinate-exposed workers from the workers who never worked 

with raffinate. Therefore, NIOSH is unable to limit the proposed class more specifically than the class 

description designated by HHS for the existing 1949 through 1957 SEC class (HHS, 2005). NIOSH 

recommends that the proposed class include all employees who worked in the Uranium Division at the 

Mallinckrodt Chemical Co., Destrehan Street Plant during the specified time period. 

7.0 Summary of Feasibility Findings for Petition SEC-00133 

This report evaluates the feasibility for completing dose reconstructions for employees at the 

Mallinckrodt Chemical Co., Destrehan Street Plant from January 1, 1958 through December 31, 1958. 

NIOSH determined that members of this class may have received radiation exposures from uranium 

and uranium progeny. NIOSH lacks sufficient information, which includes biological monitoring 

data, sufficient air monitoring information, or sufficient process and radiological source term 

information, which would allow it to estimate the potential internal thorium-230, protactinium-231, 

and actinium-227 exposures to which the proposed class may have been exposed. 

NIOSH has documented herein that it cannot complete the dose reconstruction related to this petition. 

The basis of this finding demonstrates that NIOSH does not have access to sufficient information to 

estimate either the maximum radiation dose incurred by any member of the class or to estimate such 

radiation doses more precisely than a maximum dose estimate. 

NIOSH has determined that external dose and medical X-ray dose can be reconstructed for the period 

from January 1, 1958 through December 31, 1958, using guidance and methods presented in ORAUTTKBS-0005. 

Although NIOSH found that it is not possible to completely reconstruct radiation doses for the 

proposed class, NIOSH intends to use any available internal and external monitoring data that may 

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become available for an individual claim (and can be interpreted using existing NIOSH dose 

reconstruction processes or procedures). Therefore, dose reconstructions for individuals employed at 

the Mallinckrodt Chemical Co., Destrehan Street Plant in 1958, but not qualifying for inclusion in the 

SEC, may be performed using these data as appropriate. 

8.0 Evaluation of Health Endangerment for Petition SEC-00133 

The health endangerment determination for the class of employees covered by this evaluation report is 

governed by EEOICPA and 42 C.F.R. § 83.14(b) and § 83.13(c)(3). Pursuant to these requirements, if 

it is not feasible to estimate with sufficient accuracy radiation doses for members of the class, NIOSH 

must determine that there is a reasonable likelihood that such radiation doses may have endangered 

the health of members of the class. The regulations require NIOSH to assume that any duration of 

unprotected exposure may have endangered the health of members of a class when it has been 

established that the class may have been exposed to radiation during a discrete incident likely to have 

involved levels of exposure similarly high to those occurring during nuclear criticality incidents. If 

the occurrence of such an exceptionally high-level exposure has not been established, then NIOSH is 

required to specify that health was endangered for those workers who were employed for a number of 

work days aggregating at least 250 work days within the parameters established for the class or in 

combination with work days within the parameters established for one or more other classes of 

employees in the SEC. 

NIOSH has determined that members of the class were not exposed to radiation during a discrete 

incident likely to have involved levels of exposure similarly high to those occurring during nuclear 

criticality incidents. However, the evidence reviewed in this evaluation indicates that some workers in 

the class may have accumulated chronic radiation exposures through intakes of uranium and uranium 

progeny and from direct exposure to radioactive materials. Consequently, NIOSH is specifying that 

health was endangered for those workers covered by this evaluation who were employed for a number 

of work days aggregating at least 250 work days within the parameters established for this class or in 

combination with work days within the parameters established for one or more other classes of 

employees in the SEC. 

9.0 NIOSH-Proposed Class for Petition SEC-00133 

The evaluation defines a single class of employees for which NIOSH cannot estimate radiation doses 

with sufficient accuracy. This class includes all employees of DOE, its predecessor agencies, and 

their contractors and subcontractors who worked in the Uranium Division at the Mallinckrodt 

Chemical Co., Destrehan Street Plant in St. Louis, Missouri, from January 1, 1958 to December 31, 

1958, for a number of work days aggregating at least 250 work days, occurring either solely under this 

employment or in combination with work days within the parameters established for one or more 

other classes of employees included in the SEC. 

10.0 Evaluation of Second Similar Class 

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In accordance with § 83.14(a), NIOSH may establish a second class of coworkers at the facility, 

similar to the class defined in Section 9.0, for whom NIOSH believes that dose reconstruction may not 

be feasible, and for whom additional research and analyses is required. If a second class is identified, 

it would require additional research and analyses. Such a class would be addressed in a separate SEC 

evaluation rather than delay consideration of the current claim. At this time, NIOSH has not identified 

a second similar class of employees at the Mallinckrodt Chemical Co., Destrehan Street Plant for 

whom dose reconstruction may not be feasible. 

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11 .0 Re fe re nces 

42 C.F.R. pt. 81, Guidelines for Determining the Probability of Causation Under the Energy 

Employees Occupational Illness Compensation Program Act of 2000; Final Rule, Federal 

Register/Vol. 67, No. 85/Thursday, p 22,296; May 2, 2002; SRDB Ref ID: 19391 

42 C.F.R. pt. 82, Methods for Radiation Dose Reconstruction Under the Energy Employees 

Occupational Illness Compensation Program Act of 2000; Final Rule; May 2, 2002; SRDB Ref ID: 

19392 

42 C.F.R. pt. 83, Procedures for Designating Classes of Employees as Members of the Special 

Exposure Cohort Under the Energy Employees Occupational Illness Compensation Program Act of 

2000; Final Rule; May 28, 2004; SRDB Ref ID: 22001 

42 U.S.C. §§ 7384-7385 [EEOICPA], Energy Employees Occupational Illness Compensation 

Program Act of 2000; as amended; OCAS website 

ORAUT-TKBS-0005, Basis for Development of an Exposure Matrix for the Mallinckrodt Chemical 

Company St. Louis Downtown Site and the St. Louis Airport Site, St. Louis, Missouri, Rev. 02; Oak 

Ridge Associated Universities (ORAU); June 14, 2007; SRDB Ref ID: 32277 

Cooperstein, 1981, Information on FUSRAP and Surplus Facility Sites in Missouri, with attached 

excerpts; Raymond Cooperstein; November 10, 1981; SRDB Ref ID: 14384 

DOE, 2008, DOE Office of Health, Safety and Security, EEOICPA website; 

http://www.hss.energy.gov/healthsafety/fwsp/advocacy/faclist/findfacility.cfm; last accessed on 

November 24, 2008 

Eisenbud, 1975, Early Occupational Exposure Experience with Uranium Processing; Merril 

Eisenbud, January 1, 1975; SRDB Ref ID: 10629 

HHS, 2005, HHS Designation of Additional Members of the Special Exposure Cohort-Designating a 

Class of Employees from the Uranium Division of Mallinckrodt Chemical Works, Designation letter 

and attachments; The Secretary of Health and Human Services; October 14, 2005; OSA Ref ID: 

102639 

Mallinckrodt, 1994, Columbium-Tantalum Plant Characterization Plan-Mallinckrodt, Inc. St. Louis, 

Missouri Plant; Mallinckrodt; January 10, 1994; SRDB Ref ID: 3840 

Mason, 1959, A Summary of Fifteen Years of Experience with Dust Problems in the Refining and 

Fabrication of Uranium; Mont G. Mason; September 1959; SRDB Ref ID: 15825 

USACE, 2003, Formerly Utilized Sites Remedial Action Program-St. Louis Downtown Site (SLDS), 

website; http://www.mvs.usace.army.mil/engr/fusrap/SLDS.htm; U.S. Army Corps of Engineers, St. 

Louis District; December 9, 2003; SRDB Ref ID: 12423 

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